Orthodontic treatment of improperly positioned teeth involves the application of mechanical forces to urge the teeth into correct alignment and orientation. The most common form of treatment involves use of orthodontic brackets which are small slotted bodies configured for direct attachment to the labial and buccal (facing the lips and cheeks) or lingual (facing the tongue) surfaces of the teeth, or alternatively for attachment to bands which are in turn cemented or otherwise secured around the teeth. A resilient curved arch wire is then seated in the bracket slots, and the arch wire is bent or twisted before installation whereby the restoring force exerted by the seated resilient wire tends to shift the teeth into orthodontically correct alignment. Depending on the shape of the arch wire (both round and rectangular cross-sections are in common use) and the orientation of the bracket slot, it is possible to apply forces which will shift, rotate or tip the teeth in any desired direction.
Conventional orthodontic brackets include tie wings around which small ligature wires are tied to hold the arch wire in a securely seated position in the brackets. Ligatures or some other form of fastening means are essential to insure that the activated arch wire is properly positioned around the dental arch, and to prevent the wire from being dislodged from the bracket slots during chewing of food, brushing of the teeth, or application of other forces to the wire by the patient. In addition, the arch wire is anchored at either end by brackets having tubes rather than slots therein and attached to the teeth at the opposite ends of the dental arch. These teeth, normally molars, are used to anchor the arch wire because they have the strongest root structure.
When, as is often the case, orthodontic treatment is begun when the patient is relatively young, the second molars will not yet have erupted and the arch wire will be anchored on the first molars. After the second molars come in, normally around age twelve, an orthodontist will usually want to attach a new arch wire anchored on these second molars with their stronger root structure. Because of the bends or twists in the arch wire and the varying orientations of the brackets, it would be difficult, if not impossible, for the orthodontist to thread the new arch wire through tubes in the first-molar brackets into tubes in the second-molar brackets for anchoring. Therefore, the tube in a bracket to be placed on a first molar will have a removable or severable cap, and the bracket will have tie wings enabling conversion into a slotted bracket. This allows the orthodontist to anchor the new arch wire on the second molars without removing and replacing the brackets originally attached to the first molars.
Currently, the removable cap is pried off using a cap removal tool consisting of a blade having a pointed L-shaped tip mounted on a standard scalpel handle. The tip of this tool is inserted into the end of the tube and the handle rotated away from the bracket so the tool tip presses upward against the inside surface of the cap and peels the cap off. This removal technique is unsatisfactory because it exerts a twisting or torquing force on the tooth that causes discomfort to the patient and could damage the tooth, and because the tool could slip during the prying process and injure the patient's cheek with its sharp point.
The present invention overcomes these problems by providing an orthodontic plier with opposed jaw portions that act to pry a removable cap off without exerting a twisting force on the tooth, and without an exposed tip that can damage soft mouth tissue. One jaw portion has a pointed L-shaped tip and the other a flat surface with a slot therein for receiving the L-shaped tip of the other jaw portion. The plier is configured so that the jaw portions can be moved toward one another in a substantially straight-line fashion once the tip has been inserted in a bracket tube. Thus a peeling action is exerted on the removable cap without a twisting action being exerted on the tooth to which the bracket is attached.